Hand-operated tool with switch actuator having three-position lock-off assembly

ABSTRACT

A portable, hand-operated, electric power tool such as a power shear for trimming grass or the like in which a switch actuator assembly includes a trigger on a handle for turning the tool &#39;&#39;&#39;&#39;on&#39;&#39;&#39;&#39; and &#39;&#39;&#39;&#39;off&#39;&#39;&#39;&#39;. The trigger is normally biased &#39;&#39;&#39;&#39;off&#39;&#39;&#39;&#39; and can be manually operated to the &#39;&#39;&#39;&#39;on&#39;&#39;&#39;&#39; position when the operator has his hand on the tool handle. Means is provided to automatically lock the trigger temporarily in the &#39;&#39;&#39;&#39;off&#39;&#39;&#39;&#39; position when the operator removes his hand from the tool handle, and requires intentional release to reactivate the tool. The locking means is further constructed for permanent locking when the tool is stored between uses.

1451 Dec. 18, 1973 United I States Patent 1191 Beckering et al.

HAND-OPERATED TOOL WITH SWITCH ACTUATOR HAVING THREE-POSITION LOCK-OFFASSEMBLY Primary Examiner-Robert K. Schaefer a r u 0 m .M h f PhO mh-Haa .m u m k o in BM a J S #1 0 bi mwm do a JEb m r w n e V n I 11 5 7 .l

[73] Assigneez The Black and Decker Assistant Examiner-Robert A.Vanderhye Manufacturing Company, Towson, Attorney-Leonard Bloom et al.Md. 2

[57] ABSTRACT A portable, hand-operated, electric power tool such as 221Filed: Aug. 22, 1972 21 Appl. No.: 282,768

a power shear for trimming grass or the like in which a switch actuatorassembly includes a trigger on a handle for turning the tool on and]off. The trigger is normally biased off and can be manually operated tothe on position when the operator has his hand on the tool handle. Meansis provided to automaticall Rm 9/ 12 W2 W9 20.] 9H 1 7 5 50 HU 016 To m2m m "mm 15 C WM sl e Umm mum 555 [.ll

200/169 R, 169 PB Y lock the trigger temporanly'in the of? posltion whenthe operator removes his hand from the tool handle, and requiresintentional release to reactivate the too].

References Cited UNITED STATES PATENTS 10/ I933 The locking means isfurther constructed for permanent locking when the tool is storedbetween uses.

200/ 1 57 7 Ja me PEQWESXIEEIL? 1,929,662 Wappat........................3,626,118 12 1971 Botefuhr 3,662,136 5 1972 Bienwald et al.

HAND-OPERATED TOOL WITH SWITCH ACTUATOR HAVING THREE-POSITION LOCK-OFFASSEMBLY BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The presentinvention relates to hand-operated, power tools, in which it isdesirable to provide for easy tool actuation and control, while at thesame time eliminating the likelihood that the tool will be inadvertentlyor accidentally turned on" when left unattended during use or whenstored between uses.

GENERAL DESCRIPTION OF THE PROBLEM Hand-operated, power tools of thetype to which the present invention relates are sometimes subject toaccidental activation when handled by an uninformed and- /orunexperienced person. This problem is rendered more acute in relativelysmall, light-weight devices which even a small child can pick up andaccidentally actuate. Furthermore, in the case of cordless (batterypowered) electric devices, one might be misled into thinking the deviceis not live since there is no visible line cord plugged into anelectrical outlet. Thus, the need exists for safety means renderinghand-operated power tools of the type referred to incapable ofinadvertent, or accidental actuation, when temporarily abandoned by theuser and when stored between uses, and yet which facilitates ready andeasy operation and control by the intentional user.

SUMMARY OF THE INVENTION This invention is directed to an improvedswitch actuator assembly for a hand-operated, power tool, wherein thetool may be turned on and off easily and readily, while the user keepshis hand generally in place thereon, but wherein the actuator (and tool)are automatically locked temporarily off" when the users hand isremoved.

Further, this invention includes a switch actuator assembly for ahand-operated power tool, wherein the actuator (and tool) areautomatically locked temporarily of when a user removes his handtherefrom and requires an intentional, positive release to turn the toolon," and wherein additional permanent locking means is provided for whenthe tool is stored between uses which, when operated prevents release ofthe first mentioned locking arrangement.

The above mentioned features are incorporated in this invention inasimple, compact, inexpensive, and light-weightpackage, and provides areliable, efficient, and safe tool.

BRIEF DESCRIPTION OF THE DRAWING ing portions of FIG. 2, showing theparts in a position corresponding to normalf operation of the powertool;

tions shown in FIG. 2-4.

DESCRIPTION .OF THE PREFERRED EMBODIMENT Referring to the drawing indetail; and first considering FIG. 1, a power-operated grass shear, inwhich the present invention finds use, is indicated generally at 10 andcomprises a clam-shell housing 12 including complimentary halves l6 and18 secured together by screws 19. The housing l2encloses a motor 30 anda transmission (not shown) which, when energized, pow ers the tooloutput, here a blade assembly 14 including toothed, fixed andoscillating blades l7, 15. The motror 30 is connected to a suitablepower source, such as battery means (not shown) located within thehousing 12, or conventional house current by way of a line cord 31, andis controlled by a switch 36 connected to the motor and battery means orcurrent source by leads 32, 34. The housing 12 is formed with anoverhead handle 20 adjacent which is mounted a paddle trigger 28 formingpart of a novel switch actuator assembly for operating switch 36 to turnthe tool on and off.

The switch 36 includes a body 37 trapped in place between the housinghalves l6, l8 and is provided with terminals 39, 41 to which the leads32, 34 are connected. A slider 38 on the body 37 is normally biased in adownward direction, as seen in FIGS. 2-5, by a spring 43 to open theswitch 36, and is movable upwardly to close the switch 36 and energizethe tool 10. The paddle trigger 26 is pivoted on the housing 12 by meansof trunnions 56 formed integrally with the paddle trigger 28 andjournaled in tubular bearings 58 formed integrallywith the housinghalves l6, l8 and has a paddle or finger engaging portion 26 extendingthrough cut-aways 46 in the housing halves 16, 18. The paddle trigger 28has a forward extending finger defining a ledge 68 positioned to engageand move the switch slider 38 upwardly when the trigger 28 is pivoted ina counterclockwise direction. Spring means, here a leaf spring 60 formedintegrally with the rear end of trigger 28, engages a transverse rib 62in the housing half 18 and normally biases the trigger 28 in a clockwisedirection holding it in theposition shown in FIGS. 2 and 4. v

As set out above, it is desirable that the tool be auto matically lockedtemporarily off when the operator releases his hand therefrom, such aswhen he sets the tool down, so that a positive act is necessarybeforethe tool can be turned back on. At the same time, it is importantthat the locking mechanism not engage during normal operation of thetool so as not to require frequent release. Thus, with his hand in placeon the tool, the user should be able to turn the tool on and off"without the locking mechanism coming into play. This is particularlyadvantageous in the case of cordless electric tools, since if it werenecessary to run the tool continuously to prevent the locking mechanismfrom re-engaging, the battery means would be drained too quickly.

Furthermore, it is desirable that positive, permanent lockingmeans,intended to permanently lock the tool off when stored between uses, beincorporated in the switch actuator assembly. This renders the tooltamper proof and makes it virtually impossible for an uninform'ed useror a small child to accidentally turn the tool on. Again, this isparticularly important in the case of cordless electric tools since onemight be misled into thinking that the tool cannot be energized withoutseeing an electric cord plugged into a receptacle.

Turning now to FIGS. 2-5, there is shown a lock button 44 which includesa body 82 having a pair of laterally extending trunnions 80v trapped ina pocket 70 formed by abutting ledges 71 integral with the housinghalves l6, 18. The button body 82 extends through aligned apertures 72,74 formed in ledges 71 sized to allow turning and limited rocking orpivotal movement of button 44 for purposes to'be described. The button44 has a depending blade portion 84 disposed adjacent the finger 64 ofthe paddle trigger 28, and an accessible thumb engaged portion 76located in a recess 40 in the top of the housing 12 above pocket 70.

The button 44 is adapted to be turned about its longitudinal axis, andto this end, the pocket 70 in the housing 12 is sized and shaped toreceive the trunnions 80 both longitudinally as well as transversely ofthe housing 12. When the trunnions 80 are disposed transversely of thehousing 12, as shown in FIGS. 2 and 3, they act as pivot pins for thebutton 44 so that it can be rocked or pivoted, as allowed by theapertures 72, 74, from the position shown in full lines in FIG. 2 to theposition shown in FIGS. 2 and in broken lines in FIG. 2, throughrearward pressure by the thumb against the exterior portion 76 thereof.However, when button 44 is turned to the position shown in FIG. 4, thetrunnions 80 are fitted snuggly within the pocket 70 so that no pivotalaction of the button 44 can occur.

The finger 64 of the paddle trigger 28 is provided with a generallyrectangular shaped aperture 66 therethrough (FIG. The blade portion 84of the button 44 is also generally rectangular in cross section and,when aligned with the aperture 66, allows the paddle trigger 28 to pivotin a counterclockwise direction about its trunnions 56 sufficiently soas to cause the ledge 68 to engage and move the switch slider 38upwardly and thereby close the switch 36 to turn the tool on. When,however, the blade 84 of button 44 is not aligned with the rectangularopening 66, upward movement of the paddle trigger 28 is blocked andswitch 36 cannot be closed. I

A tension spring 90 has one tang 92 wrapped around a post 94 formed onthe housing half 18, and its other tang 88 secured to the button 44 at agroove 83 located below the trunnions 80. With the button 44 oriented asshown in FIG. 2, the spring 90 holds the button 44 in the position shownso that the blade portion 84, overlays an abutment or rib 87 (FIG. 5)rearwardly of the aperture 66 in the paddle trigger finger 64. In thisposition, the button 44 temporarily prevents the paddle trigger 28 frombeing raised and from closing the switch 36. However, from thisposition, the button 44 can be manually rocked or pivoted about thetrunnions 80, in a counterclockwise direction, to the position shown inbroken lines in FIG. 2, to bring the blade portion 84 into alignmentwith the aperture 66. This is achieved through rearward pressure by theusers thumb against the portion 76 of the button 44. Then, while holdingthe button 44, so positioned, the paddle trigger 28 can be raised, byapplying pressure with the index finger against a bottom surface 48 onthe paddle Since the blade portion 84 of the button 44 is now inalignment with the aperture 66 of the paddle trigger finger 64, thelatter can be moved into the position shown in FIG. 3 where the ledge 68engages and moves the switch slider 38 upwardly. This causes the switch36 to close and turns the tool 10 on. Once the blade portion 84 of thebutton 44 has entered the aperture 66, the user can release the pressureon the portion 76 of button 44 without button 44 returning to the lockedposition shown in FIG. 2.

It will be appreciated that substantially full upward pivotal movementof the paddle trigger 28 is required to close switch 36, and conversely,switch 36 is reopened with somewhat less than full downward pivotalmovement of paddle trigger 28. Thus, the user, with his hand in positionon the handle 20 and engaged with the paddle 26, as generally shown inFIG. 1, can release the paddle trigger 28 for movement downwardly underthe force of the leaf spring 60 sufficiently far that the slider 38 canmove to open the switch 36 and turn the tool off without the bladeportion 84 of button 44 being removed fully from the aperture 66. Inother words, just with his hand in position on the tool handle 20, theuser can turn the tool on and off by, for example, pivotal movement ofthe paddle trigger 28 without the automatic locking action of the button44 being reengaged. This provides for convenient and easy use of thetool and poses no safety problem since the user, with his hands on thehandle 20, is generally aware that the tool can be energized.

However, when the user removes his hand from the handle 20, and alsofrom the paddle 26, such as, for example, when he puts the tool downduring use, the force of the spring 60 will move the paddle trigger 28fully back to the position shown in FIG. 2, whereupon the blade portion84 of button 44 is withdrawn from the aperture 66 and the button 44 ispulled back to the position shown in full lines in FIG. 2 by the spring90. Thus, when the tool 10 is left unattended during use, an uninformedor youthful observer cannot pick the tool up and accidentally turn iton. He must first release the locking button 44 by pulling rearwardly onthe head 76, and, while so holding'the button 44, pivot the paddletrigger 28 upwardly to turn the tool on. Thus, the tool 10 is renderedsafe and tamper proof in that it requires two positive, distinct andsyncronized actions to turn the tool on once it is set down by the user.

When use of the tool has been completed, and it is desired to store thetool, the locking button 44 is turned to the position shown in FIG. 4.Here, the blade portion 84 of the button 44 is disposed transversely tothe aperture 66. In this position of the parts, also represented in FIG.5, the paddle trigger 28 is permanently" locked off and cannot bemanipulated into the on position. In order to re-energize the tool, onemust rotate the button 44 through substantially back to the FIG. 2position, then rock the button 44 from the position shown in full linesto the position shown in broken lines in FIG. 2, and thereafter, whileholding the button 44 in this position, pivot the paddle trigger 28upwardly to the positions shown in FIG. 3. Thus, from the storageposition, threee separate and distinct acts must be performed in orderto re-energize the tool, thereby insuring the safety of uninformed oryouthful persons which might be tempted to tamper with the tool. Tofacilitate the described turning action of the button 44, the head 76 ofthe button is provided with a screwdriver type slot 78 adaptedto receivethe edge of a coin, a screwdriver, or other tool or device.

By the foregoing, there has been disclosed a novel switch actuator and asafety locking device therefor adapted for use with hand-operated,electric tools calculated to fulfill the inventive objects hereinaboveset forth, and while apreferred embodiment has been illustrated anddescribed in detail above, it will be appreciated that variousadditions, substitutions, modifications and omissions may be madethereto without departing from the spirit of the invention. For example,but not by way of limitation, the invention may be used inhand-operated, hand-held or other larger tools or devices, and batterypowered or corded tools or devices.

We claim:

1. In a hand-operated, power tool of the type including a housing havingan electric motor therein, tool output means exteriorly of said housingand driven by said motor, a handle connected to said housing formanipulation and control of said power tool, switch means controllingenergization of said motor and operation of said tool output means; theimprovement which comprises switch actuation means including a triggeron said handle and manually movable from a first position where saidswitch means is open and said tool off, to a second position to closesaid switch means and turn said tool on, means normally biasing saidswitch actuator means toward said first position, locking meansaccessible from said handle and movable from a first positioncooperatively engageable with said trigger to pre vent movement of saidtrigger from its first to its second position, said locking means beingnormally biased toward its first position and being manually movabletoward a second position where said trigger is then manually movable toits second position, said trigger and said locking means beingcooperatively engageable when each is in its second position wherebysaid locking means can be released and will not move back to its firstposition until said trigger is allowed to move to its first position,said trigger being movable from its second position to a third positionwhere said switch is open and said tool is off, said trigger and saidlocking means remaining engaged when said trigger is moved from itssecond to said third position, whereby said trigmediate said first andsecond position where said motor is off and said tool is de-energized,said switch operator being normally retained in said second or saidthird positions after said locking means has been released and as longas said operator keeps his hand in place on said handle, and beingautomatically movable to said first position upon removal of .saidoperators hand from said handle, said locking means being retained inits released position when saidswitch operator is in its second or thirdpositions, and moving to a locking position when said switch operator ismoved to its first position.

3. In a hand-operated, power tool of the type including a housing havingan electric motor therein, tool output means exteriorly of said housingand driven by said motor, a handle connected to said housing formanipulation and control of said power tool, switch means controllingenergization of said motor and operation of said tool output means; theimprovement which comprises switch actuation means including a triggeron said handle and manually movable from a first postion where saidswitch means is open and said tool off, to a second postion to closesaid switch means and turn said tool on, means normally biasing saidswitch actuator means toward said first position, locking meansaccessible from said handle and movable: from a first positioncooperatively engageable with said trigger to prevent movement of saidtrigger from its first to its second position, said locking means beingnormally biased toward its first position and being manually movabletoward a second position out of said first mentioned cooperativelyengageable relation with said trigger where said trigger is thenmanually movable to its second position, said trigger and said lockingmeans being cooperatively engageable in a second relation when each isin its second position whereby said locking means can be released andwill not move back to its first position until said trigger is allowedto'move to its first position, said trigger being movable from itssecond position to a third position where said switch is open and saidtool is off, said trigger and said locking means remaining in saidsecond cooperatively engageable relation when said trigger is in saidthird position, whereby said trigger may be moved from its third to itssecond position, turning said tool off and on without manuallyrepositioning said locking means.

4. A portable, hand-held and manipulated power tool comprising a housinghaving an electric motor therein,

ger may be moved from its third to its second position,

comprising a housing having an electric motor therein,

tool means driven by said motor and supported upon said housing, saidhousing including a handle, switch means including a switch operator onsaid handle and normally engaged by an operator's hand when the latteris in position on said handle, said switch operator being movable from afirst position where said motor is off and said tool is de-energized, toa second position where said motor is on and said tool is energized,means normally biasing, said switch operator toward said first position,manually releasable means locking said switch operator in said firstposition, said switch operator being movable through a third positionintertool means driven by said motor and supported upon said housing,said housing including a handle, switch means including a switchoperator on said handle and normally engaged by arr-operator's hand'when the latter is in position on said handle, said switch operatorhaving an aperture therein and being movable from a first position wheresaid motor is off and said tool is deenergized, to a second positionwhere said motor is on and said tool is energized, means normallybiasing said switch operator toward said first position, manuallyreleasable means normally positioned in confronting, abuttingrelationship with and locking said switch operator in said firstposition, said locking means being movable to a switch operatorreleasing position where it aligns with and includes a portionreceivable in said aperture when said switch operator is moved to itssecond position, whereby to allow movement of said switch operator toits second position, said switch operator being movable through a thirdposition intermediate said first and second position where said motor isoff and said tool is deenergized, said locking means portion remainingreceived in said aperture while said switch operator is in its thirdposition, said switch operator being normally retained in said second orsaid third positions after said locking means has been released and aslong as said operator keeps his hand in place on said handle, and beingautomatically movable to said first position upon removal of saidoperators hand from said handle.

5. A portable, hand-held and manipulated power tool comprising a housinghaving an electric motor therein, tool means driven by said motor andsupported upon said housing, said housing including a handle, switchmeans including a switch operator on said handle and normally engaged byan operators hand when the latter is in position on said handle, saidswitch operator having an aperture therein and being movable from afirst position where said motor is off and said tool is deenergized, toa second position where said motor is on and said tool is energized,means normally biasing said switch operator toward said first position,manually releasable means normally positioned in confronting, abuttingrelationship with and locking said switch operator in said firstposition, said locking means being movable to a switch operatorreleasing position where it aligns with and includes a portionreceivable in said aperture when said switch operator is moved to itssecond position,- whereby to allow movement of said switch operator toits second position, said switch operator being movable through a thirdposition intermediate said first and second position where said motor isoff and said tool is deenergized, said locking means portion remainingreceived in said aperture while said switch operator is in its thirdposition, said switch operator being normally retained in said second orsaid third positions after said locking means has been re-' leased andaslong as said operator keeps his hand in place on said handle, andbeing automatically movable to said first position upon removal of saidoperators hand from said handle, said locking means being retained inits released position when said switch operator is in its second orthird positions, and moving to a locking position when said switchoperator is moved to its first position. i

6. A portable, hand-held and manipulated power tool comprising a housinghaving an elecric motor therein, tool means driven by said motor andsupported upon said housing, said housing including a handle, switchmeans including a switch operator on said handle and normally engaged byan operators hand when the latter is in position on said handle, saidswitch operator having an aperture therein and being movable from afirst position where said motor is off and said tool is deenergized, toa second position where said motor is on and said tool is energized,means normally biasing said switch operator toward said first position,manually releasable means normally positoned in confronting, abuttingrelationship with'and locking said switch operator in said firstposition, said locking means being movable to a switch operatorreleasing position where it aligns with and includes a portionreceivable in said aperture when said switch operator is moved to itssecond position, whereby to allow movement of said switch operator toits second position, said switch operator being movable through a thirdposition intermediate said first and second position where said motor isoff and said tool is deenergized, said locking means portion remainingreceived in said aperture while said switch operator is in its thirdposition, said switch operator being normally retained in said second orsaid third positions after said locking means has been released and aslong as said operator keeps his hand in place on said handle, and beingautomatically movable to said first position upon removal of saidoperators hand from said handle, said locking means being movable to apermanent locking position when said switch operator is in its firstposition whereby said locking means is not receivable in said apertureand said switch operator is permanently locked off.

7. A portable, hand-held and manipulated power tool comprising a housinghaving an electric motor therein, tool means driven by said motor andsupported upon said housing, said housing including a handle, switchmeans including a switch operator on said handle and normally engaged byan operators hand when the latter is in position on said handle, saidswitch operator having an aperture therein and being movable from afirst position where said motor is off and said tool is deenergized, toa second position where said motor is on and said tool is energized,means normally biasing said switch operator toward said'first position,manually releasable means normally positioned in confronting, abuttingrelationship with and locking said switch operator in said firstposition, said locking means being movable to a switch operatorreleasing position where it aligns with and includes a portionreceivable in said aperture when said switch operator is moved to itssecond position, whereby to allow movement of said switch operator toits second position, said switch operator being movable through a thirdposition intermediate said first and second position where said motor isoff and said tool is de-energized, said locking means portion remainingreceived in said aperture while said switch operator is in its thirdposition, said switch operator being normally retained in said second orsaid third positions after said locking means has been released and aslong as said operator keeps his hand in place on said handle, and beingautomatically movable to said first position upon removal of saidoperators hand from said handle, said locking means being retained inits released position when said switch operator is in its second orthird positions, and moving to a locking position when said switchoperator is moved to its first position, said locking means beingmovable to a permanent locking position when said switch operator is inits first position whereby said locking means is not receivable in saidaperture and said switch operator is permanently locked off.

1. In a hand-operated, power tool of the type including a housing havingan electric motor therein, tool output means exteriorly of said housingand driven by said motor, a handle connected to said housing formanipulation and control of said power tool, switch means controllingenergization of said motor and operation of said tool output means; theimprovement which comprises switch actuation means including a triggeron said handle and manually movable from a first position where saidswitch means is open and said tool off, to a second position to closesaid switch means and turn said tool on, means normally biasing saidswitch actuator means toward said first position, locking meansaccessible from said handle and movable from a first positioncooperatively engageable with said trigger to prevent movement of saidtrigger from its first to its second position, said locking means beingnormally biased toward its first position and being manually movabletoward a second position where said trigger is then manually movable toits second position, said trigger and said locking means beingcooperatively engageable when each is in its second position wherebysaid locking means can be released and will not move back to its firstposition until said trigger is allowed to move to its first position,said trigger being movable from its second position to a third positionwhere said switch is open and said tool is off, said trigger and saidlocking means remaining engaged when said trigger is moved from itssecond to said third position, whereby said trigger may be moved fromits third to its second position, turning said tool off and on, withoutmanually repositioning said locking means.
 2. A portable, hand-held andmanipulated power tool comprising a housing having an electric motortherein, tool means driven by said motor and supported upon saidhousing, said housing including a handle, switch means including aswitch operator on said handle and normally engaged by an operator''shand when the latter is in position on said handle, said switch operatorbeing movable from a first position where said motor is off and saidtool is de-energized, to a second position where said motor is on andsaid tool is energized, means normally biasing said switch operatortoward said first position, manually releasable means locking saidswitch operator in said first position, said switch operator beingmovable through a third position intermediate said first and secondposition where said motor is off and said tool is de-energized, saidswitch operator being normally retained in said second or said thirdpositions after said locking means has been released and as long as saidoperator keeps his hand in place on said handle, and being automaticallymovable to said first position upon removal of said operator''s handfrom said handle, said locking means being retained in its releasedposition when said switch operator is in its second or third positions,and moving to a locking position when said switch operator is moved toits first position.
 3. In a hand-operated, power tool of the typeincluding a housing having an electric motor therein, tool output meansexteriorly of said housing and driven by said motor, a handle connectedto said housing for manipulation and control of said power tool, switchmeans controlling energization of said motor and operation of said tooloutput means; the improvement which comprises switch actuation meansincluding a trigger on said handle and manually movable from a firstpostion where said switch means is open and said tool off, to a secondpostion to close said switch means and turn said tool on, means normallybiasing said switch actuator means toward said first position, lockingmeans accessible from said handle and movable from a first positioncooperatively engageable with said trigger to prevent movement of saidtrigger from its first to its second position, said locking means beingnormally biased toward its first position and being manually movabletoward a second position out of said first mentioned cooperativelyengageable relation with said trigger where said trigger is thenmanually movable to its second position, said trigger and said lockingmeans being cooperatively engageable in a second relation when each isin its second position whereby said locking means can be released andwill not move back to its first position until said trigger is allowedto move to its first position, said trigger being movable from itssecond position to a third position where said switch is open and saidtool is off, said trigger and said locking means remaining in saidsecond cooperatively engageable relation when said trigger is in saidthird position, whereby said trigger may be moved from its third to itssecond position, turning said tool off and on without manuallyrepositioning said locking means.
 4. A portable, hand-held andmanipulated power tool comprising a housing having an electric motortherein, tool means driven by said motor and supported upon saidhousing, said housing including a handle, switch means including aswitch operator on said handle and normally engaged by an operator''shand when the latter is in position on said handle, said switch operatorhaving an aperture therein and being movable from a first position wheresaid motor is off and said tool is de-energized, to a second positionwhere said motor is on and said tool is energized, means normallybiasing said switch operator toward said first position, manuallyreleasable means normally positioned in confronting, abuttingrelationship with and locking said switch operator in said firstposition, said locking means being movable to a switch operatorreleasing position where it aligns with and includes a portionreceivable in said aperture when said switch operator is moved to itssecond position, whereby to allow movement of said switch operator toits second position, said switch operator being movable through a thirdposition intermediate said first and second position where said motor isoff and said tool is deenergized, said locking means portion remainingreceived in said aperture while said switch operator is in its thirdposition, said switch operator being normally retained in said second orsaid third positions after said locking means has been released and aslong as said operator keeps his hand in place on said handle, and beingautomatically movable to said first position upon removal of saidoperator''s hand from said handle.
 5. A portable, hand-held andmanipulated power tool comprising a housing having an electric motortherein, tool means driven by said motor and supported upon saidhousing, said housing including a handle, switch means including aswitch operator on said handle and normally engaged by an operator''shand when the latter is in position on said handle, said switch operatorhaving an aperture therein and being movable from a first position wheresaid motor is off and said tool is de-energized, to a second positionwhere said motor is on and said tool is energized, means normallybiasing said switch operator toward said first position, manuallyreleasable means normally positioned in confronting, abuttingrelationship with and locking said switch operator in said firstposition, said locking means being movable to a switch operatorreleasing position where it aligns with and includes a portionreceivable in said aperture when said switch operator is moved to itssecond position, whereby to allow movement of said switch operator toits second position, said switch operator being movable through a thirdposition intermediate said first and second position where said motor isoff and said tool is deenergized, said locking means portion remainingreceived in said aperture while said switch operator is in its thirdposition, sAid switch operator being normally retained in said second orsaid third positions after said locking means has been released and aslong as said operator keeps his hand in place on said handle, and beingautomatically movable to said first position upon removal of saidoperator''s hand from said handle, said locking means being retained inits released position when said switch operator is in its second orthird positions, and moving to a locking position when said switchoperator is moved to its first position.
 6. A portable, hand-held andmanipulated power tool comprising a housing having an elecric motortherein, tool means driven by said motor and supported upon saidhousing, said housing including a handle, switch means including aswitch operator on said handle and normally engaged by an operator''shand when the latter is in position on said handle, said switch operatorhaving an aperture therein and being movable from a first position wheresaid motor is off and said tool is de-energized, to a second positionwhere said motor is on and said tool is energized, means normallybiasing said switch operator toward said first position, manuallyreleasable means normally positoned in confronting, abuttingrelationship with and locking said switch operator in said firstposition, said locking means being movable to a switch operatorreleasing position where it aligns with and includes a portionreceivable in said aperture when said switch operator is moved to itssecond position, whereby to allow movement of said switch operator toits second position, said switch operator being movable through a thirdposition intermediate said first and second position where said motor isoff and said tool is deenergized, said locking means portion remainingreceived in said aperture while said switch operator is in its thirdposition, said switch operator being normally retained in said second orsaid third positions after said locking means has been released and aslong as said operator keeps his hand in place on said handle, and beingautomatically movable to said first position upon removal of saidoperator''s hand from said handle, said locking means being movable to apermanent locking position when said switch operator is in its firstposition whereby said locking means is not receivable in said apertureand said switch operator is permanently locked off.
 7. A portable,hand-held and manipulated power tool comprising a housing having anelectric motor therein, tool means driven by said motor and supportedupon said housing, said housing including a handle, switch meansincluding a switch operator on said handle and normally engaged by anoperator''s hand when the latter is in position on said handle, saidswitch operator having an aperture therein and being movable from afirst position where said motor is off and said tool is de-energized, toa second position where said motor is on and said tool is energized,means normally biasing said switch operator toward said first position,manually releasable means normally positioned in confronting, abuttingrelationship with and locking said switch operator in said firstposition, said locking means being movable to a switch operatorreleasing position where it aligns with and includes a portionreceivable in said aperture when said switch operator is moved to itssecond position, whereby to allow movement of said switch operator toits second position, said switch operator being movable through a thirdposition intermediate said first and second position where said motor isoff and said tool is de-energized, said locking means portion remainingreceived in said aperture while said switch operator is in its thirdposition, said switch operator being normally retained in said second orsaid third positions after said locking means has been released and aslong as said operator keeps his hand in place on said handle, and beingautomatically movable to said first position upon removal of saidoperator''s hand from said handle, said lockIng means being retained inits released position when said switch operator is in its second orthird positions, and moving to a locking position when said switchoperator is moved to its first position, said locking means beingmovable to a permanent locking position when said switch operator is inits first position whereby said locking means is not receivable in saidaperture and said switch operator is permanently locked off.